Existing pepper varieties are suitable for manual harvesting, which often requires growers to send crews into the field multiple times. Labor cost for manual harvest for pepper accounts for more than 50% of total production cost in the United States (Hawkes and Libbin, 2000, Crop cost and return estimates in New Mexico, 1998, New Mexico Agric. Expt. Station, Las Cruces, N. Mex.) but decreases to less than 10% of production costs with mechanical harvest (Eastman et al., 1997, Impact of increasing wages on New Mexico chile production, New Mexico Agric. Expt. Station Res. Report No. 714, Las Cruces, N. Mex.). A pepper plant must possess specific attributes for mechanical harvesting. Currently, there are no genotypes that have been specifically bred for mechanical harvesting for many of the commercially important pepper varieties. Existing varieties have indeterminate growth habit resulting in continuous fruit set.
Work on adapting or developing machines specific for the mechanical harvesting of chili peppers has been on-going at least from the early 1980's (see, e.g., Funk et al., 2011, A systems approach to chile harvest mechanization, International Journal of Vegetable Science, 17:296-309). To date the mainstream machine-solution research activities to harvest fresh pepper have focused on developing machines that are suitable to existing pepper ideotypes. Thus, past approaches have been focused on designing a machine based on existing crop architecture (e.g., in-determinant habit, distributive fruit set, multiple picking), rather then breeding peppers for adaptability for easier and more reliable mechanical harvesting. Assuming indeterminate growth habit of existing varieties, non destructive multiple-picking type of machines have been tested but have not been widely accepted by pepper growers and producers.
The main focus of past breeding attempts to adapt peppers to mechanical harvest has focused almost exclusively on red paprika type peppers. Almost all fruit of commercially grown red paprika peppers turn red at the end of the season, even immature fruit, and physical damage to the pod, therefore, does not matter that much as they go directly to the dryer anyway.
Attempts have also been made to adapt the machines used for harvesting red paprika peppers to see if they could be used for harvesting other types of peppers, such as green Jalapeño peppers. This approach has proven impractical and economically unviable since doing so requires multiple harvests for a single field and there is a huge risk of subsequent disease outbreak between the harvests due to the physical damage to the plant by the harvesters. Currently, there is insufficient research publicly available on the genetic controls of destemming and pod detachment force as well as determinant plant growth habit, all of which are important characteristics to consider in designing a machine-harvestable pepper plant.
The current invention meets a long felt need for a pepper plant ideotype suitable for machine harvesting and provides new elite pepper varieties useful for mechanical harvesting combined with other highly desirable agronomic traits.